As high-load work is increasingly common in industrial fields, there is an increased need to study measures that allow a load applied to human joints to be reduced for the increased convenience of workers. According to this demand, a wearable robot which a worker wears and moves has been proposed as one such measure. The present disclosure proposes a technique for extracting intended torque of a wearer so as to allow the wearable robot to accurately move according to the intent of the wearer.
In a method and apparatus for compensating a stick motion generated at a quadrant changing position in numerical control machine tools disclosed in Korean Unexamined Patent Application Publication No. 10-2008-0079590, a real position estimator 21 estimates a real position of a movable body corresponding to a position instruction signal to generate a real position signal. A differentiator 22 differentiates the real position signal to obtain a speed signal. Then, an integrator 24 integrates the speed signal, thereby generating a displacement signal from a position at which a moving direction of the movable body is reversed. An absolute value calculator 25 obtains an absolute value of the displacement signal. A friction characteristic estimator 26 obtains a rate of change of displacement of friction force or friction torque. A multiplier 27 multiplies the rate of change of the displacement by the speed signal, and obtains a rate of change of time. An integrator 28 integrates the rate of change of time, and estimates the friction force or the friction torque.
However, in spite of this measure, additional measures are still required for realizing proper movement corresponding to the intent of the wearer by obtaining friction in real driving in real time, and by compensating a driver with the obtained friction.
Further, a force-torque sensor is generally attached to the wearable robot in order to measure torque applied by a user. This sensor has an influence on an increase in weight of a mechanism as well as in price.
Thus, since the force-torque sensor is used to calculate the wearer-intended torque, a way to effectively calculate the wearer-intended torque without using this expensive sensor is required.
The foregoing is intended merely to aid in the understanding of the background of the present disclosure, and is not intended to mean that the present disclosure falls within the purview of the related art that is already known to those skilled in the art.